In the discussion that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
A conventional munition includes a container housing, a high explosive, and optionally, fragments. Upon detonation of the high explosive, the container is torn apart forming fragments that are accelerated outwardly. In addition, to the extent that fragments are located within the container, these internal fragments are also propelled outwardly. The “kill mechanism” of the conventional fragmentation warhead is the penetration of the fragments (usually steel) into the device or target, which is kinetic energy dependent.
Reactive fragments are used to enhance the lethality of such munitions. A reactive fragment enhances the lethality of the device by transferring additional energy into the target. Upon impact with the target reactive fragments release additional chemical or thermal energy thereby enhancing damage, and potentially improving the lethality of the munition. The reactive fragment employs both kinetic energy transfer of the accelerated fragment into the target as well as the release chemical energy stored by the fragment. Moreover, the released chemical energy can be transferred to the surroundings thermally through radiant, conductive, and/or convective heat transfer. Thus, unlike purely kinetic fragments, the effects of such reactive fragments extend beyond the trajectory thereof.
Some reactive fragments employ composite materials based on a mixture of reactive metal powders and an oxidizer suspended in an organic matrix. However, certain engineering challenges are often encountered in the development of such reactive fragments. For example, a minimum requisite amount of activation energy must be transferred to the reactive fragments in order to trigger the release of chemical energy. There has been a general lack of confidence in the ignition of such reactive fragments upon impact at velocities less than about 4000 ft/s. The reactive fragments must possess a certain amount of structural integrity in order to survive shocks encountered upon launch of the munition, but must also begin to combust upon impact with a target. Thus, such conventionally constructed reactive fragments present an engineering challenge; they favor a low launch velocity to enhance survival of the fragment upon launch, yet also benefit from higher launch velocities which are desirable for energetic initiation.
Thus, it would be advantageous to provide an improved reactive fragment which may address one or more of the above-mentioned concerns.
Relevant publications include U.S. Pat. Publication Nos. 3,961,576; 4,996,922; 5,538,795; 5,700,974; 5,912,069; 5,936,184; 6,627,013; 6,679,960; 6,736,942; 6,863,992; 2001/0046597; 2002/0069944; 2003/0164289; and 2005/0142495, the entire disclosure of each of these publications is incorporated herein by reference.